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performed according to the presented solution, with the restriction however,
that only such absolute given control. data are introduced as are necessary for
a unique solution. The coordinates of the model thus obtained are then trans-
formed in a second computational step by three translations, three rotations
and a scaling factor in such a way that the sum of the squares of the residual
distances between the model and all the given control coordinates becomes a
minimum. Obviously, with such a method, the photogrammetrically obtained model
. 18 being interpolated into the configurations of the given control coordinates.
(Compare [3] ana [6] )
(b): Trend Conditional Equations ;
Quite similar to the treatment of & metric conditional equation, it
is possible to introduce & certain trend condition known to exist between the
points to be triangul&áted, and which is mathematically expressed by & functional
relation existing between the coordinates of such points. In a general sense,
such conditional equations will resemble metric conditional equations, except
that they will not necessarily have any absolutely giyen parameters. Moding
on the mathematical character of a specific trend, the number of points involved
in such a trend condition will vary. Correspondingly, the smallest possible |
Subdivision in the process of establishing the final normal equation system by
partitioning will be determined by the number of points combined by any one or
several trend conditional equations. |
E. A Solution for Triangulating Points not Included in the Least Squares
Treatment for the Orientation Parameters
Despite the possibility of incorporating any number of relative control
points in the general analytical solution for a specific photogrammetric
triangulation problem, it sometimes may be desirable to triangulate separately
additional points of the model, Consequently, for those points, an independent
coordinate determination becomes necessary. The positions of the corresponding
rays are determined by the elements of orientation as obtained from an inde
pendent preceding least squares adjustment and the corresponding plate measure-
ments, It is obvious that these rays will not intersect due to unavoidable
measuring errors. They must be made to intersect so that the sum of the squares
of the corrections to be applied to the original plate measurements is a minimum.
29